1. Field of the Invention
This invention relates to a reaction mechanism of a hydraulic control valve assembly which is operated by a power source such as a hydraulic pump.
2. Description of the Prior Art
In conventional reaction mechanisms of a hydraulic booster having an input piston and a reaction transmitting piston, pressure in a power chamber scarcely acts on the input piston until the pressure in the power chamber increases up to a predetermined value. At this value the pressure in the power chamber acts on the input piston only when the power chamber reaches the predetermined value to engage the input piston with the reaction transmitting piston such that the reaction was transmitted to the driver, with a resulting shock given to the driver upon engagement between the reaction transmitting piston and the input piston.